The problem is when I GET the model in the route it is assigning an ember generated id to the subtype in belongsTO relationship.
{ name: "jack" , "entityType" : { "code" : "codeA", "id" : "ember100"} }

Is there a way I can stop it from assigning an id. Is there a primary key concept for subtypes? And how to make sure these generated ids are not serialized on POST?